/* eslint-disable ts/no-this-alias */
/* eslint-disable func-style */
import { globalState } from '../app/global-state';

export function externalBarcodeScannerBuilder(this: any) {
	const self = this;
	this.numbersOnly = false;
	this.minChars = 10;
	this.timeOut = 650;
	this.firefoxHack = false;
	this.scanned = null;

    this._registered = false;
	this._chars = [];
	this._pressed = false;
	this._t = null;
	this._charMap = new Object();
	this._initCharMap = function () {
		this._charMap[32] = ' ';
		this._charMap[33] = '!';
		this._charMap[34] = '"';
		this._charMap[35] = '#';
		this._charMap[36] = '$';
		this._charMap[37] = '%';
		this._charMap[38] = '&';
		this._charMap[39] = '\'';
		this._charMap[40] = '(';
		this._charMap[41] = ')';
		this._charMap[42] = '*';
		this._charMap[43] = '+';
		this._charMap[44] = ',';
		this._charMap[45] = '-';
		this._charMap[46] = '.';
		this._charMap[47] = '/';
		this._charMap[48] = '0';
		this._charMap[49] = '1';
		this._charMap[50] = '2';
		this._charMap[51] = '3';
		this._charMap[52] = '4';
		this._charMap[53] = '5';
		this._charMap[54] = '6';
		this._charMap[55] = '7';
		this._charMap[56] = '8';
		this._charMap[57] = '9';
		this._charMap[58] = ':';
		this._charMap[59] = ';';
		this._charMap[60] = '<';
		this._charMap[61] = '=';
		this._charMap[62] = '>';
		this._charMap[63] = '?';
		this._charMap[64] = '@';
		this._charMap[65] = 'A';
		this._charMap[66] = 'B';
		this._charMap[67] = 'C';
		this._charMap[68] = 'D';
		this._charMap[69] = 'E';
		this._charMap[70] = 'F';
		this._charMap[71] = 'G';
		this._charMap[72] = 'H';
		this._charMap[73] = 'I';
		this._charMap[74] = 'J';
		this._charMap[75] = 'K';
		this._charMap[76] = 'L';
		this._charMap[77] = 'M';
		this._charMap[78] = 'N';
		this._charMap[79] = 'O';
		this._charMap[80] = 'P';
		this._charMap[81] = 'Q';
		this._charMap[82] = 'R';
		this._charMap[83] = 'S';
		this._charMap[84] = 'T';
		this._charMap[85] = 'U';
		this._charMap[86] = 'V';
		this._charMap[87] = 'W';
		this._charMap[88] = 'X';
		this._charMap[89] = 'Y';
		this._charMap[90] = 'Z';
		this._charMap[91] = '[';
		this._charMap[92] = '\\';
		this._charMap[93] = ']';
		this._charMap[94] = '^';
		this._charMap[95] = '_';
		this._charMap[96] = '`';
		this._charMap[97] = 'a';
		this._charMap[98] = 'b';
		this._charMap[99] = 'c';
		this._charMap[100] = 'd';
		this._charMap[101] = 'e';
		this._charMap[102] = 'f';
		this._charMap[103] = 'g';
		this._charMap[104] = 'h';
		this._charMap[105] = 'i';
		this._charMap[106] = 'j';
		this._charMap[107] = 'k';
		this._charMap[108] = 'l';
		this._charMap[109] = 'm';
		this._charMap[110] = 'n';
		this._charMap[111] = 'o';
		this._charMap[112] = 'p';
		this._charMap[113] = 'q';
		this._charMap[114] = 'r';
		this._charMap[115] = 's';
		this._charMap[116] = 't';
		this._charMap[117] = 'u';
		this._charMap[118] = 'v';
		this._charMap[119] = 'w';
		this._charMap[120] = 'x';
		this._charMap[121] = 'y';
		this._charMap[122] = 'z';
		this._charMap[123] = '{';
		this._charMap[124] = '|';
		this._charMap[125] = '}';
		this._charMap[126] = '~';
		this._charMap[127] = '';
		this._charMap[128] = '€';
		this._charMap[129] = '';
		this._charMap[130] = '‚';
		this._charMap[131] = 'ƒ';
		this._charMap[132] = '„';
		this._charMap[133] = '…';
		this._charMap[134] = '†';
		this._charMap[135] = '‡';
		this._charMap[136] = 'ˆ';
		this._charMap[137] = '‰';
		this._charMap[138] = 'Š';
		this._charMap[139] = '‹';
		this._charMap[140] = 'Œ';
		this._charMap[141] = '';
		this._charMap[142] = 'Ž';
		this._charMap[143] = '';
		this._charMap[144] = '';
		this._charMap[145] = '‘';
		this._charMap[146] = '’';
		this._charMap[147] = '“';
		this._charMap[148] = '”';
		this._charMap[149] = '•';
		this._charMap[150] = '–';
		this._charMap[151] = '—';
		this._charMap[152] = '˜';
		this._charMap[153] = '™';
		this._charMap[154] = 'š';
		this._charMap[155] = '›';
		this._charMap[156] = 'œ';
		this._charMap[157] = '';
		this._charMap[158] = 'ž';
		this._charMap[159] = 'Ÿ';
		this._charMap[160] = '';
		this._charMap[161] = '¡';
		this._charMap[162] = '¢';
		this._charMap[163] = '£';
		this._charMap[164] = '¤';
		this._charMap[165] = '¥';
		this._charMap[166] = '¦';
		this._charMap[167] = '§';
		this._charMap[168] = '¨';
		this._charMap[169] = '©';
		this._charMap[170] = 'ª';
		this._charMap[171] = '«';
		this._charMap[172] = '¬';
		this._charMap[173] = '';
		this._charMap[174] = '®';
		this._charMap[175] = '¯';
		this._charMap[176] = '°';
		this._charMap[177] = '±';
		this._charMap[178] = '²';
		this._charMap[179] = '³';
		this._charMap[180] = '´';
		this._charMap[181] = 'µ';
		this._charMap[182] = '¶';
		this._charMap[183] = '·';
		this._charMap[184] = '¸';
		this._charMap[185] = '¹';
		this._charMap[186] = 'º';
		this._charMap[187] = '»';
		this._charMap[188] = '¼';
		this._charMap[189] = '½';
		this._charMap[190] = '¾';
		this._charMap[191] = '¿';
		this._charMap[192] = 'À';
		this._charMap[193] = 'Á';
		this._charMap[194] = 'Â';
		this._charMap[195] = 'Ã';
		this._charMap[196] = 'Ä';
		this._charMap[197] = 'Å';
		this._charMap[198] = 'Æ';
		this._charMap[199] = 'Ç';
		this._charMap[200] = 'È';
		this._charMap[201] = 'É';
		this._charMap[202] = 'Ê';
		this._charMap[203] = 'Ë';
		this._charMap[204] = 'Ì';
		this._charMap[205] = 'Í';
		this._charMap[206] = 'Î';
		this._charMap[207] = 'Ï';
		this._charMap[208] = 'Ð';
		this._charMap[209] = 'Ñ';
		this._charMap[210] = 'Ò';
		this._charMap[211] = 'Ó';
		this._charMap[212] = 'Ô';
		this._charMap[213] = 'Õ';
		this._charMap[214] = 'Ö';
		this._charMap[215] = '×';
		this._charMap[216] = 'Ø';
		this._charMap[217] = 'Ù';
		this._charMap[218] = 'Ú';
		this._charMap[219] = 'Û';
		this._charMap[220] = 'Ü';
		this._charMap[221] = 'Ý';
		this._charMap[222] = 'Þ';
		this._charMap[223] = 'ß';
		this._charMap[224] = 'à';
		this._charMap[225] = 'á';
		this._charMap[226] = 'â';
		this._charMap[227] = 'ã';
		this._charMap[228] = 'ä';
		this._charMap[229] = 'å';
		this._charMap[230] = 'æ';
		this._charMap[231] = 'ç';
		this._charMap[232] = 'è';
		this._charMap[233] = 'é';
		this._charMap[234] = 'ê';
		this._charMap[235] = 'ë';
		this._charMap[236] = 'ì';
		this._charMap[237] = 'í';
		this._charMap[238] = 'î';
		this._charMap[239] = 'ï';
		this._charMap[240] = 'ð';
		this._charMap[241] = 'ñ';
		this._charMap[242] = 'ò';
		this._charMap[243] = 'ó';
		this._charMap[244] = 'ô';
		this._charMap[245] = 'õ';
		this._charMap[246] = 'ö';
		this._charMap[247] = '÷';
		this._charMap[248] = 'ø';
		this._charMap[249] = 'ù';
		this._charMap[250] = 'ú';
		this._charMap[251] = 'û';
		this._charMap[252] = 'ü';
		this._charMap[253] = 'ý';
		this._charMap[254] = 'þ';
		this._charMap[255] = 'ÿ';
	};
	this._initCharMap();

	this._onKeyUp = function (e) {
		const value = e.which ? e.which : e.keyCode;

		if (value > 31) {
			clearTimeout(self._t);
			self._pressed = false;

			// var inputVal = String.fromCharCode(value);
			let inputVal = self._charMap[value];
			if (inputVal == null || inputVal.length == 0) {
				inputVal = String.fromCharCode(value);
			}

			if (self.numbersOnly) {
				if (value >= 48 && value <= 57) {
					self._chars.push(inputVal);
				}
			} else {
				self._chars.push(inputVal);
			}

			if (self._pressed == false) {
				self._pressed = true; // <- SET THIS BEFORE SETTING THE TIMER
				self._t = setTimeout(() => {
					// = 10) {
					self._verify();
					self._cleanUp();
				}, self.timeOut);
			}
		}
	};

    this.isRegistered = function(): boolean {
        return self._registered;
    }

    this.setRegistered = function(registered: boolean) {
        self._registered = registered;
    }

	this.register = function () {
        self._chars = [];
		self._pressed = false;
		globalState.addEventListener('keyup', self._onKeyUp);
	};

	this.unregister = function () {
		globalState.removeEventListener('keyup', self._onKeyUp);
	};

	this._pushChar = function (which) {
		self._chars.push(String.fromCharCode(which));
		// self._verify();
	};

	this._verify = function () {
		if (self._chars.length >= self.minChars) {
			let barcode = self._chars.join('');
			const firstThree = barcode.substring(0, 3);

			if (self.firefoxHack && !isNaN(firstThree)) {
				const firstThreeNum = Number(firstThree);
				if (firstThreeNum < 255) {
					const charVal = String.fromCharCode(firstThreeNum);
					if (charVal == self._chars[3]) {
						const textLength = barcode.length;
						let retVal = '';

						if (textLength % 4 == 0) {
							for (let i = 3; i < textLength; i += 4) {
								retVal += self._chars[i];
							}
						}

						if (retVal.length >= self.minChars) {
							barcode = retVal;
						}
					}
				}
			}

			if (self.scanned != null) {
				if (barcode != null) {
					barcode = barcode
						.replace(/(\r\n|\n|\r)/g, '')
						.split('»')
						.join('1');
				}

				self.scanned(barcode);
				self._cleanUp();
			}
		}
	};

	this._cleanUp = function () {
		clearTimeout(self._t); // <- CLEAR TIMER IF IS NOT BARCODE
		self._chars = [];
		self._pressed = false;
	};
}

/** Configuration options for the external barcode scanner. */
interface ExternalBarcodeScannerOptions {
	/** When true, only numeric characters (0-9) are captured from the scanner input. */
	numbersOnly?: boolean;
	/** Minimum number of characters required for input to be considered a valid barcode scan. */
	minChars?: number;
	/** Time in milliseconds to wait after the last keystroke before processing the input. */
	timeoutMs?: number;
	/** Callback invoked with the scanned barcode string when a valid scan is detected. */
	scanned?: (code: string) => void;
}

/**
 * Static facade for managing an external barcode scanner that listens for rapid keyup events.
 * Maintains a singleton instance internally — use {@link register} / {@link unregister} to control the listener
 * and {@link setOptions} to configure behaviour.
 */
export default class ExternalBarcodeScanner {
	private static _externalBarcodeScannerInstance: any = null;

	/** Starts listening for barcode scanner keyup events. */
	static register() {
		const instance = ExternalBarcodeScanner.getInstance();
        if (instance.isRegistered()) {
            return;
        }
        instance.register();
        instance.setRegistered(true);
	};

	/** Stops listening for barcode scanner keyup events. */
	static unregister() {
		const instance = ExternalBarcodeScanner.getInstance();
        instance.unregister();
        instance.setRegistered(false);
	};

	/** Applies the provided options to the scanner instance. Only keys present in `opts` are updated. */
	static setOptions(opts: ExternalBarcodeScannerOptions) {
		const instance = ExternalBarcodeScanner.getInstance();
		if ('numbersOnly' in opts) {
			instance.numbersOnly = opts.numbersOnly;
		}

		if ('minChars' in opts) {
			instance.minChars = opts.minChars;
		}

		if ('timeoutMs' in opts) {
			instance.timeOut = opts.timeoutMs;
		}

		if ('scanned' in opts) {
			instance.scanned = opts.scanned;
		}
	}

	private static getInstance() {
		if (ExternalBarcodeScanner._externalBarcodeScannerInstance == null) {
			// eslint-disable-next-line new-cap
			ExternalBarcodeScanner._externalBarcodeScannerInstance = new externalBarcodeScannerBuilder();
		}

		return ExternalBarcodeScanner._externalBarcodeScannerInstance;
	}
}